Hydraulic spring closing mechanism for circuit breakers-prevention of unintentional closing



Jan. 19, 1960 H MITCHELL 2,922,011

HYDRAULIC SPRING CLOSING MECHANISM FOR CIRCUIT BREAKERS-PREVENTION OF UNINTENTIONAL CLOSING Filed July 1, 1957 2 Sheets-Sheet 2 ff /lrrae/VEW WMM;

United States Patent() Harold H. Mitchell, La Canada, Calif., assignor, by mesne assignments, to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Application July 1, 1957, Serial No. 669,294

, Claims. (Cl. 200-153) My present invention relates to circuit breakers and more particularly to circuit breaker operating mechanisms which are particularly adapted to operate oil circuit breakers although they may readily be arranged to operate other types of circuit breakers.

Specifically, my invention relates to mechanisms for closing the circuit breaker, said mechanism being associated, however, with mechanisms for opening the circuit breaker and being so arranged that the selected operation of either closing or opening the breaker may be performed in accordance with the condition of the circuit breaker at any particular time, and without interference by the closing mechanism with the opening mechanism, or viceversa. t

Heretofore, systems have been provided for closing circuit breakers, such closing mechanisms and the connection thereof to the circuit breaker being so arranged that the circuit breaker will at all times be trip free, both during the closing operation and after the closing operation is completed while the closing mechanism is still in the closing position.

In some circuit breakers, the closing mechanism is operated bya closing spring which is initially compressed preparatory to a closing operation by a hydraulic system operating in a cylinder in which the closing spring is compressed by a piston.

When the spring is permitted to expand, the piston is driven to operate a closing member to effect a closing of the circuit breaker.

Frequently, in mechanisms of this type, the freeing of the spring from compression, so that it may operate to move the piston to' close the circuit breaker, is achieved by opening a valve, so that hydraulic fluid pressure may be equalized on both sides of the piston.

In other words, the spring is maintained in com- Y pressed condition by hydraulic pressure on the side of the piston opposite the spring. 'The equalization of pressure isthen achieved by'for instance, the opening of a I' valve which permits hydraulic fluid to flow and equalize pressurey on both vsides of the piston. When such equalized pressure is 'reached or approached, then the compressed spring is free to expand to operate the closing mechanism. v

While the utilization of such hydraulic mechanism for initially compressing the powerful closing spring provides simplicity and convenience in operation, and the closing spring may thus be compressed manually by operation of a manual pump for forcing the hydraulic liuid against the piston to compress the spring, nevertheless, the possibility exists that in the event of a leak inthe valve, the cylinder or the hydraulic line, pressure on both sides ofthe piston may either approach equalization or actually become equal, so that the spring may expand to Yclose the circuit breaker.`

My invention has for its primary object the provision of mechanism for positively locking theclosing member and the piston inopen position and maintaining the Patented Jan. 19, 1960 ice . Y 2 spring in compressed position when the circuit breaker is intended to be and remains open.

Whether or not equalization or substantial equalization on both sides of the piston occurs, accidentally or otherwise, during the period when the circuit is to remain open, my invention has for a further object, the provision of means operable simultaneously and as a result of the operation of a closing handle to release said locking means when it is desired to close the circuit breaker.

In other words, the circuit breaker closing mechanism is locked in the open position and remains locked in an open position until a positive operation is performed intended to etect a closing of the circuit breaker.

A further object of the present invention is the arrangement of the locking means for the closing mechanism so that operation of a valve which is intended to equalize the hydraulic pressure to permit closing will simultaneously release the locking mechanism.

The foregoing and many other objects of my invention will become apparent in the following description and drawings in which:

Figure 1 is a schematic view showing generally the operation of my circuit breaker.

Figure 2 is a vertical View in cross-section showing my novel circuit breaker mechanism and the locking device in the open position.

Figures 2A and 2B are highly schematic views both showing the arrangement of the links and toggles of my novel circuit breaker in the open position thereof.

Figure 3 is a view corresponding to that of Figure 2 showing my novel circuit breaker operating mechanism in the closed position thereof.

Figures 3A and 3B are highly schematic views both showing the arrangement of the links and toggles of my novel circuit breaker in the closed position thereof.

Figure 4 is a view corresponding so that of Figures 2 and 3, showing my novel circuit breaker operating mechanism in the trip-free condition.

Figures 4A and 4B are highly schematic views both showing the arrangement of the links and toggles of my novel circuit breaker in the trip-free position thereof.

Referring iirst to Figures 1 and 2, I have shown schematically in Figure 1, the basic hydraulic operation of my circuit breaker operating mechanism and in Figure 2, the elements as they appear in actual commercial form with certain portions of the hydraulic connections omitted.

Essentially, my novel circuit breaker closing mechanism comprises a closing ram 10, which is connected to a piston 11 operating in cylinder 12.

Closing springs 13 are compressed between the lower face of pistoon 11 and the lower interior surface 14 of the cylinder 12, the said springs v13 being located in section 15 of the cylinder below the piston 11.

The closing ram 10 extends upwardly through opening 16 in the head 17 of cylinder 12, appropriate sealing means 18 being provided at the opening 16 to retain hydraulic pressure.

The cylinder head 17 is secured to the cylinder 12 in any appropriate manner, as for instance, by the securement means 19 and is provided with two' connected intersecting passages 20, 21, which form part of the hydraulic line.

Passage v21 is connected through the T-member 22 to the hydraulic line 23 which, through the check valve I24 (not shown in Figure 2, but shown in Figure 1), is connected by line 23a to the pump 25 (also not shown in Figure 2). Y

Pump 25 is connected by exhaust line 26 to the T- connection 27, which in turn, is connected -to opening 28 vin the-lowefend of'fthe cylinder 'communicating with chamberi 15- of the-cylinder. e A 'y A bypass or parallel path is provided from the upper chamber- 30 o f cyl inder to the lower chamber 15 of cylinder- 12,through the-'passage 20,4 21; theA T- conf asaaoli f of a circuit breaker into and out ot' engagement with i complementary"-contacts.I

The movement of the movable contacts toward engagement is achieved by clockwise rotation of contact -operating shaft 50, supportedin any appropriate manner v for rotation in appropriate bearings (not shown) between that the `axial lengthl ofl'each chambervaries-'as piston. t

11 is rn'ovednpwardly'or downwardly in the cylinder 12.

In order toemove the closing ram 10l from thenp 1 l position of Figure 4l to.k the full open positionof Figure 2, it is necesary tofforce the piston-.'11 down against the*V Y increasirigbias -of-the ^closing spring13r In order to perform 'thisVA operation,j pump 25 is operto draw iiuid'from the llower chamber -15 throughv line 26 and-Lto pump the fluid through line 2341,-checkvalve 24, lines 23-and 2()',"-`21, into the upper chamber y30- of cylinder I21S-.w At this time, the loperatingvalve 32 vis closed. Asthe uid isthus pumpedgintothe upper chamber 30 of cyl-V inder 115,- thelincrease `inrpressure forces the piston: 11 down from the position of Figures 3 and' 4 to theposition of Figure 2-to-charge the-closing spring'13;

While theq closing spring 13 is here for convenienceA referred to as a single spring; the closing spring 13. may actually vbe-a pluralityv of' springsas shown in Figures 2, 3 and 4, each positioned about guide rods 35, 36, 37,

v ated either manually orby any other appropriatemeans;A .l

the walls of the operating mechanism housingV 51.

The opening of the circuit breakerffrom the'positioiifgny of Figure 3to that vof either'FiguresrZ orY 4, is achieved..

by rotation of the contact operating shaft 50 in acounter'- clockwise direction.V operating'shaftV 50'of Figures 2, Bland 4, show the directhe next operation, whether toward closing .or opening. The shaft 5t) may be connected in any suitable manner to the movable contacts of `the"circuit..breaker. One

-method shownin highly schematic form, is by means of an arm Y52 which is part of bell cranklever 53 keyed A, to the contact operating shaft S0 and therefore rotatable with the shaft 50.:

Lever'52 'foroperating oneor more sets ofymovable contacts, vmay asV shown in highly; schematic ,form in Figures 2B, 3B and 4B,'befconnectedY to a bell crank` `the position of Figure 3 to the position of Figures 2 j" securedto theeunder'surface of cylinder 11, and having extensions-slidably vreceived in-recesses 38, 39 'in the lower ylindersurfaceg'or head 14 and in the bearing plate 40ffonlthesprings;` s-

' When itheoperation of the pump 25l ceases, Y the, check valve 2,4 serves `to maintain the pressure in-lines 23, 20,

21 andv cham-ber30;ane-tnusg-maimain the piston 11,111

Y the lower lor compressed-position of Figure Zagainst Athe bias of springsyl.

In order to 'release this -pressure-and permit springs 13 to raise the piston lleand'jclosing ram 10V-from the 4position of Figure 2 to theclosedposition of Figure 3,

contactroperating shaft fis ,connected bypin 621to i u 'lever 63, which through toggle pin 64 is inA toggle rela- A it is nownecesary to permit hydraulic pressure in chamu equalize-theI pressures chamber 30 above the piston,

11 and: chamber- 15y below the piston 11.v This is achieved by the4-closing valve 32which is normally Yclosed1whenk the circuit breaker fis opened, but which, when opened establishes a connection vfrom upperchamber 30 through passages `-20,'21,31` and -valve 32 to passage 33 to th lower chamber 15. v

Pressure ist then'equalized byi this connection between tered to the expansion ofthe compressed springs 13 in thelicondition` of- Figure2,- other than that lrequired` 11 and;closingjram 10 upwardly from the position ,of` Figure V. 7. to 4the positionv of Figure"3.to,close the circuitY breaker;

The 1ocking.rneans which is thefbasic subject matter ,Y

of the present invention, comprises the over-center toggle 100 which include s links 101,- and Y102 connected in toggle relation with each other by ,toggle pin 1033.

lever by'pin54, bell cranklever 5,5being rotatable on a pin orrshaft 56. The opposite end of the bell crank The arrows on` circular contact Vtion'in which the shaft will V'next be rotated to perform;

lever 55 Ais connected by pin 57 ,to a verticallymovable ,l contact arm58 carrying, at its lowerpend, the movable. contacts v59 for cooperation with the complementary contacts 60.

Consequently., rotation of contact carrying shaft from or 4, will rraise the lever 52 and will. rotateY bell crank t lever 55 to 4drive `thecontactrarm 58 and contacts 759 downwardly away from the. complementary contacts l60 to open the circuit breaker.

Similarly,an opposite rotatlon Yof, contactl voperating v '-.j shaft from the position of YFigure`2 to the` lposition of ,s Figure -3 willresult in movement of the movable contacts 59 into engagementswith complementary Ycontacts 60 as shown in Figure 3B. i Y l Leverarm' 61 of bell'crank vlever 52 'keyed to the,

Pins 62 and 64 are Afloating ypinsin the sense that y. they are not connected to any stationary bearing, .but are moved to various positions by ,various forces exerted Y .either on the pinsor on.the toggle links towhich vthey aV-bearing against whichthe end 10a of 'closingl ramv10 are connected. t

Pin 64 is providediwith a roller '66' which serves as may bear in ,moving the circuitbreaker from the open s s position of Figure Zto the closed position of FigureV 3. chambers-30t and-15,A andno1resistance^-is then encounv Link 65 is connected by iloatingpin 67. to link 68, the: j opposite end of which is connected to a stationary or shaft 69.

The op'ertaion of this locking means, however, can be understood best after the basic circuit l,breaker operating toggle meshenism'isfdescribed. Hence. the-Specic de- .Y scription of ad lockingv toggle s will be vdeferred untilI the oper iongof -thes/circuit'lbreaker toggle per se canH be made clear.

course;A

Latch link 72 is provided with an extension the latch roller 75.

71 to'latch link 72. j Y

. Link 72 is rotatably mounted on stationary pinn'7v3.

- z Link 6s is in'roggle relation-through pin mwithfiinr 70, the opposite end of which is connected by floating pin i 74 carry-ing. i

When the rcircuit breaker isclosed as showniin Figy ure 3, the opening bias on the circuit-breaker contacts isV transmitted through bell crank lever 52 to thepin62..

The toggle consisting of links 63 and 65 isundercenter and is supported, as thefcase may be, either onthe4 end 10a offtheclosingram 10 or on the.V support latch 80,

which support latch engages pin 64; f

ported Yby the under-centery toggle con/iprisinglinks g. and The bias, therefore, at toggleg170e68isr-in a f direction :tocause itto Yfurther.extend-theEv toggle, iand. f-

,hencanxove pin .71;.upwardly..f 1f`he latch link 72 o w ng.;;

The toggle comprising; links 63,165 isnsupportedat its opposite end ragainstnthe pin,\67,which fin'.turnf is:sup-

to the fact that its latch roller 75 is engaged by the latch 81, locks this upward movement of pin 71 and link 72, and thereby maintains all of the toggles in the position shown in Figure 3 when the circuit breaker is closed.

Latch 81 is rotatably mounted on shaft 82 and is biased in any suitable manner towards the position shown in Figures 2 and 3.

Preferably, latch S1 is connected to a latching bar 83 which is rotatably mounted as above pointed out, and the latching bar 83 is provided with a trip lever 84 which may be engaged `by a tripping device (not shown). The trip lever bears against stop 85.

The tripping device is so arranged that it may be selectively either manually operated or operated in respouse. to current conditions on the line in which the circuitbreaker is connected to rotate the latch lever 84 and the latch member 81 in a counterclockwise direction with respect to Figures 3 and `4. This removes the blocking support by latch 81 to latch roller 75 and pin 74, and hence, removes the support from pin 71.

Toggle 70-72 is thus allowed to extend fromthe position of Figure 3 to the position of Figure 4, and the subsequent movement of pin 67Yto the left with respect to the rfigures pulls the roller 66 off the surface 10a of closing ram and also pulls'the toggle pin 64 or an extension thereof off the latch member 80; the circuit breaker now opens in response to the bias on its movable contact even though the closing ram 10 is in the closing position as shown in Figure 4. This is the trip-free condition of the circuit breaker.

Either the toggle 63-65 or the toggle 70-72 may be provided with a relatively light resetting spring tending to rest the toggles toward the condition of Figure 2. This spring which is not shown, but which is well understood, v,is suiciently light so that it will not interfere in any way with the closing springs 13 or with the opening bias springs of the circuit breaker, but is also suiciently strong'so that it will restore either one of the two toggles to which it is connected to the condition of Figure 2; so thatthe circuit breaker is reset for closing when the closing ram 10 is drawn down to the closed position and the latch member 81 is re-engaged with latch roller 75 in the position shown in Figure 2.

To summarize, the operation of the toggle mechanisms, the moving of closing ram 10 from the position of Figure 2 to theposition of Figure 3, extends the toggle 65-63 to a substantially extended but under-center position, rotating theshaft 50 and extension 52 of bell crank lever 53 in a direction to close the circuit breaker; The extended toggle 6365vis supported by the -toggle 70-68 at pin 67, this latter toggle being in turn supported atv pin 71 by the latch lever` 72, the latch roller 75 and the latch 81. y

Trip-free operation is, of course, a result ofthe closing of the circuit breaker on an over current or fault condition which operates the trip member or the result of `anyv other tripping operation which occurs while the closing ram 10 is in the elevated positionl of Figure 3.

In this case, the toggles operate as previously pointed out to open the circuit breaker, the toggles assuming the position of Figure 4 with the roller 66 bearing against the side of ram 10. While the circuit breaker is open in this instance, sincethe closing ram 10 is'extended the toggles cannot fully collapse in response to the light` toggle restoring spring referred to. When the closing ram is lwithdrawn to the position of Figure 2, then the toggles may collapse and the latch reset, as shown in Figure 2.

When the circuit breaker is closed `and the pin 64 of toggle 63-65 is supported on member 80, the closing ram may be withdrawn and the circuit breaker will remain closed.

It will be obvious, that when the circuit 'breaker is open in the position of Figure 2, any operationof the hyrdaulic, mechanismy which will release the pressure 6 in chamber 30 or'permit equalization of pressure in chambers 30 and 15 of the cylinder 12 will result in the expansion of the closing spring 13 and a movement of the parts from the open position of Figure 2 to the closed position of Figure 3.

v This invention has for its special object another lock device so arranged that'as long as the valve 32 is intended to stay closed and thereby hold the piston 11 in its lowered position and compress spring 13, the entire Vtoggle mechanism remains locked in the position of Figure. 2.

My invention has for its further object the arrangement of the operating mechanism of the valve 32 in such a manner that opening the valve to permit equalization of` pressure and the expansion of springs 13 will automatically release the interlock. In order to provide this interlock and means which will prevent the operation of the closing springs 13 to lift the ram 10 until an actual operation of that type is desired, I provide on the contactv operating shaft 50 an additional crank 90 keyed thereto. Crank 90 is connected by pin 91 to the toggle 100 consisting of link 102, 101 and toggle pin 103. Link 101 of toggle 100 is connected to the stationary pivot 104.

When all of the toggle elements of the circuit breaker have moved to the open position of Figure 2, toggle 100 moves over-center around its knee pin 103 tending actually to break in the other direction, that is, in a direction to move pin 103 to the left of the line connection pins 104 and 91.

Extension 105 of link 101 bearing against stop pin 106 (Figure 3) of link 102 prevents this break of the toggle in the opposite direction from occurring while, nevertheless, permitting the toggle 100 to move just beyond center. With the toggle 100 broken just beyond center, anyattempt to rotatethe contact operating shaft in a clockwise direction with respect to Figure 2 will be defeated since the extended toggle 100 prevents rotation of crank arm 90 which is keyed to the shaft 50.

Hence, any force tending to raise the closing ram 10 would be blocked by reason of the fact that, with contact operating shaft S0 held against rotation, lever 61 cannot rotate clockwise and link 63 cannot rise.

Since all of the links are so arranged that they assume the position shown in Figure 2, when the circuit breaker is Open, thelockingV toggle 100 extends into locking po sition automatically on opening of Vthe circuit breaker mechanism. The locking extension of toggle 100 even takes place when the opening occurs in response to tripfree operation, as shown in Figure 4, since the condition of'toggle 100 depends only on the angular position of lever 90 keyed -to the contact operating shaft "50.

When now it is desired to close the circuit breaker, not only must the pressure in chamber 30 of cylinder 12 be released or equalized to permit the springs 13 to expand, but also the lock achieved by toggle 100 must be broken. For this purpose, toggle 100 must be moved back over-center, that is, with the knee pin 103 moving toward the right with respect to Figure 2; when this toggle breaks over-center to the right, it offers no further resistance to the clockwise movement of crank arm and contact operating shaft 50. Any appropriate means may be provided to move the knee pin 1.03 of toggle to the right, including apush rod engaging an extension of the knee pin 103.

Freferably, since the closing operation should result from operation of handle ofthe control valve 32, that is, the operation of the handle 110 to open the control valve 32, the said handle 110 may be interlocked with means automatically operable on movement of the handle 110 to push the knee pin 103 of toggle 100 through center, so that it may break to permit rotation upwardly of the end of crank arm 90. Handle 110 is so arranged that the valve 32 is closed when the handle 110 is in the upposition of Figure 2, and so that valve 32 is open the stationarypivot MS-'on' thefhousing w51 `of :thefoperat kall ofgthe parts return kto the position. of

. open position/"ofi said s' contacts" and preventing rotation of thek 'shaft in Ithel'said first"direction--by'saidclosing aaaagoraz;

ing mechanism. The left-hand extension ofthelever 112.. being epivotally connected 'fate 4114i fto the fpull'- rod114a the lower end` of fwhichis pi-votally. connected tat :L tothey valve control handle 110;

guresis, :provided with' the; cam surface. Y1116,' the camsurface registering with an extension of pin 163.' When now the handle 110'is ,movedl downwardly, pull rod llaa is alsol moved downwardly, the left-hand end of leverllg is moved downwardly and the cam surface 116 of the.lever 112 rises-up. f The raising of-the cam surface 1116 ofrleverv 112 pushes-the knee pin extension 103- to the right with respect to AFigure 2,V breaking'the toggle-100 back through` center toward'the right, so that the toggle may now` collapse lon further movement of handle 110 j nisrn may-be operated to draw down the closing'ram 10 V while the-member@ maintains the toggle mechanism nV the position of Figure 3. In Ithis case, the handle 110 may be raised'backv tothe position of YFigure 2 and the cam lever IM2 restored to the position of Figure?. with- Vout interfering with the vclosed condition of the circuit breaker. When theecircuit breaker is, therefore, tripped, Figure V2, and the automatic lock takes place. Y

closed;with the closing ram withdrawn, a leak. should' vcomplernentar'y:contactg` 2. lnawitchgeareihayin position for -ssai'd contacts; means associated with Vsaid toggleforgblocking'breaking.andzcollapse ofsaid'ftoggle -V v in the `.over center position; said blocking means and over centerrpo'sition lof saidftoggle'locking said'shaft in the lopen positionfofrsaid contactsiand preventing.frota-4 `tion ofthe shaftinthesaid rst direction by 'said closing;v L

means;andadditionakmeans .operable on said toggle for member comprising a shaft rotatable'ina firstV direction occur causing the closing ramV to rise accidentally, then, 1 as shown in Figure 4;.thisv condition will -notv interfere t with thetrippin'g vof the circuit breaker.

Thereafter, in order to 'reclose the circuit breaker, the

chamber 30 of cylinder 12V must be recharged meaning,'-of course,` that handle-1f10 must be raisedtothe positionV of FigureV 2, andy on rwithdrawal oftheV closing ram 10,VY n

all elements will be restored to the open andv interlocked, position of Figure 2.V t

In the foregoing I have described my invention solely;

of. Since many variationsV andy -modifications of the inventioni-.will now be obvious to thoseskilled in the art,.

contained but only by the*appendediclaims.`

l claim: t

- in connection with specific illustrative4 embodiments there- 5 0 -v I prefer to be bound not by the specificdisclosures herein l. In switchgear having a movable contact and'a com plementary contact, a movable contact operating member comprising a shaft rotatable in a first :direction to;ef

fect a closure of said contacts and in a second direction:

to 'effect a closure of said contacts'and inV a second di-V rectionto'efect an opening of saidl contacts; Aclosingmeans; operable 4to rotatesaid'shaft in said first direction; and locking means fordefeating the'` operation of" said closinglrneans-.and maintaining! saidshaft in the' open tlf while thecircuit breaker is :closed and remains f position forfsaid contacts; said' lockingmeans comprisc ing a crank'onusaidshaft; a toggle comprising one vlink `connected'atfone end thereofitosaid crank, a toggle pin at thefotherY end ofs'aid link; asecond rlink'con'nected at one .endifth'ere'of to said toggle gpin, the other end iofv the saidxsecond link Ybeing stationarily pivoted; said togf l' f'gle pin i'movingi over center whensaid -shaft is in the? 'open positionvforsaid contactsjlmea'ns associated with 'l said toggle for blocking breaking andcollapseof said togglein-.Lthe over .center position; said v'blocking means -andoverf center .position-of said toggle locking said shaft in theopen positionk of said -contacts andv peventing rolV .tation '.of. the. shaft in the .said iirst direction byY said closing means. and? additional meansoperable on'sa'idftoggle for moving sad toggle'from the blocked position through centerto-'a position where it -is free'vto collapse tofper-V mit rotationofsaidshaft inrs'aid first directionV in rev sponse'nt'o operation 'of :said closingfme'ans; said addii tional means being operable in response to operation Vof 'saidclosing."means.:A

4l" Inzswitchgear'ihaving ai -lleffect a closurefoflsaidicontactsfand in aV second'direcf tiontoeifect Van opening of said contacts;fclosinglmeanszoperable'to'rotate Isaid fshaft inis'aidl ,first'fdirectiong'and v locking* meanszifor" defeating theoperationof said ,close-f` ing meansfandmaintainingsaidfshaft in the open posi- .Y 5 Y on said shaft; a toggle comprising one-link connected.v

at one end thereof to said crank, a toggle pin atthe 6,5v

other end of said link; a secondflink connected at one` end thereof to said toggle pin, theother end of` thesaid second link being stationarilyApivoted;y said togglepin y i. moving over center when said shaft is in the open po` sition for said contacts; means associated with said toggle for blocking breakingand collapse of said toggle'in the over',y center position; vsaid blocking meansiand overA` Vtion fosaidcontacts; f'said locking means comprising a' f Vcrank bnfsaid shaft; aetoggle comprising one-link cone.' nectedLatfoneYendthereoftosaidcrankya-toggle pin* i at the other end ofsa'id link; asecond link "connectedat one end -thereofto Vsaid toggle pin, Vthe other end .of the said second link being vstationarily pivoted; said togglev lAlpin, movingvover centerwhen said` shaft is'ifthen open center liposition* of 'said toggle. locking saidshaft inthef".

meansf-ed is position! iforesaid contacts;- means1 lassociated with saidY toggle Yfor blocking'lbreakng*and; collapsefofsaid toggle` in the o vcr center position; said blocking means andfover f center ipo'sition offsaiditoggleflocking*said-shaft n Vthe open position f Y fsaid'l contacts :andi preventing frot'atio'n' of 'the's'lzraftv in lithe said|-rst=l direction byVs said*'closingl movable contact: zand." rw' movable'. :contactoperating s member 'rc'omprisingf'azshaft rotatable inra vfirst:- direction.. v z to effect faf'closure..ofzsaidlcontacts and" in a second di-iv` vrection-s oaefe'ct can. opening of said contacts; closing.. meansgloperable .tot rotate. said. shaft in .said-tirstfdire .i' i tion; and locking means for defeating the operation'of i 4.said closingtmeans andmaintaining said shaft inthe open i position foi'rsaid'contacts; said locking means comprisiing fa crank :on-saidi shaft; atoggle comprising one link' connectedatfone end; thereof tosaidcrankya' togglepin at the other end of said link; a .secondlink connected at onesendf'thereofto said togglefpin'; the" other end'of. .the saidtsecondlink :being stationarily pivoted; said tog# gle pinmovingfover center when said shaft is in the open L -f movable contactand a corn- Y plcmentaryfcontact, i a movable' contact operating -member comprisingfa -'shaft rotatable? in a frstldirectio'n to t 9 means and additional means operable on said toggle for moving said toggle from thej blocked position 4through center to a position wherev itisffree to collapse to `permit rotation of vsaid 'shaft in said first direction in response to operation of vsaid closing means; a handle for initiating the operation ofsaid closingmeans; said handle being also connected to operate said additional means.

5. In switchgear havinga movable contactrand a complementary contact, a .movable contact operating member comprising a shaft rotatable in a first direction to effect a closure of said' contacts and in a second direction to effect an openingl of, :said contacts; closing means operable to rotate said shaft'in said first direction; and lockingy means for defeating the operation of said closing means and maintaining said shaft in the open position for said contacts; said locking means comprising a crank on said shaft; a togglercomprising one link connected at one end thereof to said crank, a toggle pin at the other end of said link; a second link connected at one end thereof to said toggle pin, the other end of the said second link being stationarily pivoted; said toggle pin moving over center when said shaft is in the open position for said contacts; means associated with said toggle for blocking breaking and collapse of said toggle in the over center position; said blocking means and over center position of said toggle locking said shaft in the open position of said contacts and preventing rotation of the shaft in the said first direction by said closing means and additional means operable on said toggle for moving said toggle from the blocked position through center to a position where it is free to collapse to permit rotation of said shaft in said first direction in response to operation of said closing means; said additional means comprising a cam member pivotally mounted adjacent said toggle pin, rotation of said cam member in one direction causing the cam to engage said toggle pin and move the same through center to permit collapse of said toggle; a member for initiating the operation of said closing means; said last mentioned member being also connected to rotate said cam member in said one direction.

6. In switchgear having a movable contact and a complementary contact, movable contact operating apparatus including a crank; said crank being rotatable in a first direction upon a closure of said contacts and in a second direction upon an opening of said contacts; closing means engageable with said movable contact operating apparatus to effect a closure of said contacts; and locking means for defeating the operation of said closing means and maintaining said contacts in open position; said locking means being connected to said crank and consisting of a toggle comprising one link connected at one end thereof to said crank, a toggle pin at the other end of said link; a second link connected at one end thereof to said toggle pin, the other end of the said second link being stationarily pivoted; said-toggle pin moving over center when said contacts are in the open position; means associated with said toggle for blocking breaking and collapse of said toggle in the over center position; said blocking means and over center position of said toggle locking said crank in the open position and preventing closure thereof.

7. In switchgear having a movable contact and a complementary contact; movable contact operating means; a closing ram engageable with said movable contact operating means to effect a closure of said contacts; spring means for biasing said closing ram for operation thereof in the closing direction; means for charging said spring means and for restraining the same against operation of said ram in the closing direction; and means for locking said movable contact against unintended closure; said means including a crank associated with said movable contact operating means; said crank being rotatable in a first direction upon a closure of said contacts and in a second direction upon an opening of said contacts;

n said link; asecond link connected at one end thereof to said toggle pin, the other end of the said second link being stationarily pivoted; said toggle pin moving over center when said contacts are in the open position; means associated with said toggle for blocking breaking and collapse of said toggle in the over center position; said blocking means and over center position of said toggle locking said contacts in the open position.

8. In switchgear having a movable contact and a complementary contact; movable contact operating means; a closing ram engageable with s aid movable contact operating means to effect a closure of said contacts; spring means for biasing said closing ram for operation thereof in the closing direction; means for charging said spring means and for restraining the same against operation of said ram in the closing direction; and means for locking said movable contactv against unintended closure; said means including a crank associated with said movable contact operating means; said crank being rotatable in a first directoin upon a closure of said contacts and in a second' direction upon an opening of said contacts; and a toggle comprising one link connected at one end thereof to said crank, a toggle pin at the other end of said link; a second link connected at one end thereof to said toggle pin, the other end of the said second link being stationarily pivoted; said toggle pin moving over center when said contacts are in the open position; means associated with said toggle for blocking breaking and collapse of said toggle in the over center position; said blocking means and over center position of said toggle locking said contacts in the open position and additional means operable in response to release of said spring restraining means for moving said toggle from a blocked position through center to a position Where it is free to collapse to permit movement of said crank in said first direction to close said contacts.

9. In switchgear having a movable contact and a complementary contact; movable contact operating means; a closing ram engageable with said movable contact operating means; a closing ram engageable with said movable contact operating means to effect a closure of said contacts; spring means for biasing said closing ram for operation thereof in the closing direction; hydraulic means for charging said spring means and a valve for maintaining the hydraulic means in condition to restrain said spring means in charged position and means for locking said movable contact against unintended closure; said means including a crank associated with said movable contact operating means; said crank being rotatable in a first direction upon a closure of said contacts and in a second direction upon an opening of said contacts; and a toggle comprising one link connected-at one end thereof to said crank, a toggle pin at the other end of said link; a second link connected at one end thereof to said toggle pin, the other end of the said second link being stationarily pivoted; said toggle pin moving over center when said contacts are in the open position; means associated with said toggle for blocking breaking and collapse of said toggle in the over center position; said blocking means and over center position of said toggle locking said contacts in the open position.

10. In switchgear having a movable contact and a complementary contact; movable contact operating means; a closing ram engageable with said movable contact operating means; a closing ram engageable with said movable contact operating means to effect a closure of said contacts; spring means for biasing said closing ram for operation thereof in the closing direction; hydraulic means for charging said spring means and a valve for maintaining the hydraulic means in condition to restrain said spring means in charged position and means for locking said movable contact against unintended closure; said means including acrank associated with said mov- Y able ebntaetfoperating means;said?crankaengurotatable:

Y in a second `direction upon a'nfopeningxf saidcontac'ts y and a-to'ggle comprising `on`e link connected atoneendl Vover center when said contacts arevin theopen posi# Y movenientffof"s'aidcraix A t i y Y thereof to said crank, a toggle pin at `fthe'other end: 5" 'Said c'ntactsy-and; means mrnnerctig's of said link; a second link connected' atonefend-ithereof secondmembersfoij simlviltarieesvoperatin: to 'said toggle pin, the other end oftthesaid` secondi Y i. L Y link being stationarily pivoted; said togglefpin'moving-f Referie'scitd mathe ijle'oftvhis ptntrmsg tion; means associated with said toggle forbloking '1'0 5 11;?. .UNITED STATESPATENJTS l* breaking and collapseof saidtoggle in the over, center 708,710' "Hewlett: i'''iee.-' -ISePf 951-1902 positiomsaid blocking'meanscandfover centen-position y 1 ,f y x of saidtoggle locking said contactsfin `'thefopen' position FOREI-GN'PATENTS v 1 l i and a flrst.member for'operatingjsaid valve to release 526,219 il: Canada?n nngrlune Y12,11956 `r 

